© Provided by The iThe actor Michael J Fox is a high profile Parkinson's patient. He has actively campaigned for more research into the disease (Photo: Getty)
A smell test that could help diagnose Parkinson's Disease up to 10 years before the main symptoms appear is on the horizon after a breakthrough in sniffing technology.
The new tests use capsules of aromatic oil which can be crushed and pulled apart easily to give a precise amount of oil to deliver just the right odour potency.
They are much cheaper and more accurate than the traditional 'scratch and sniff' tests, which are typically used to assess a person's sense of smell more generally and where the amount of odour released largely depends on the strength and number of scratches.
As such, the new technology has the potential to be widely used to screen for a number of diseases that cause an early loss of smell, such as Alzheimer's Disease and acute respiratory infections such as Covid.
More than 90 per cent of Parkinson's patients suffer from loss of smell and previous studies suggest that the right smell test could identify those at high risk of developing the disease up to 10 years before symptoms appear.
Taking a smell test could give early warning of the disease, so that those deemed at high risk could be monitored and tested with traditional diagnostic tools.
Because the tests are cheap they could be offered as part of a routine checkup at the GP. Meanwhile people concerned that they may have a condition associated with loss of smell could report to the doctor for a test.
"You might think that testing your ability to smell is something easy that you can do yourself - but surprisingly, many people do not even notice when they lose their sense of smell," said Dr Ahmed Ismail, of Queen Mary University of London, adding that only 15 per cent of Covid-19 patients noticed a deterioration in their sense of ability to smell, even though that is a common symptom.
"We have developed the encapsulation technology and the smell testing kit, but now we need to refine the odours used and their threshold for each disease in which the loss of smell is a key symptom. It might be that for each disease there is a [smell] threshold and so the power of the aroma is related to the disease you have."
The new smell test technology was tested on Parkinson's patients in a study published in the Journal of the Royal Society Interface.